If an aircraft serving a sector of your itinerary does not have a cabin class you have selected, you will be placed in a lower or higher cabin class.
For example, a passenger has a First Class ticket for a London-Hong Kong-Sydney-Hong Kong-London itinerary. If the selected Hong Kong to Sydney flight does not have a First Class cabin, the passenger will be seated in Business or Economy class, subject to availability.
If the requested cabin class is not available in one of the sectors in your itinerary, you will be notified during the booking process. Please note that your entire itinerary is priced in the cabin class you requested.